JP2801098B2 - Welding method for welded joints - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for welding a welded joint in which a metal plate is interposed between two metal members, and the two metal members are integrally welded to each other via the metal plate.

[0002]

2. Description of the Related Art For example, automotive parts include a metal plate (base material) between two metal members such as a nut member and a collar member.
There have been used various types of components in which the two metal members are coaxially and integrally welded and connected via the metal plate material. When this type of component is welded, projection welding is generally performed. For example, a ring-shaped projection is provided on a welding joint surface of a work, and welding work is performed via the ring-shaped projection. Japanese Patent Application Laid-Open No. 60-143218, Japanese Utility Model Application Laid-Open No.
122983, etc.). Furthermore, a method of performing welding work in a three-layered state through each welding protrusion, with the positions of the welding protrusions of the reinforcing base material and the auxiliary base material being abutted on each surface of the basic base material while being shifted from each other. Has been proposed (see Japanese Patent Publication No. 3-24311).

[0003]

However, in the above-mentioned prior art, a problem has been pointed out that a ring-shaped or a plurality of projections must be provided in advance on the work, and the production cost of this kind of work increases. . In addition, in projection welding, the welding current is concentrated on the projections, and the welding starts from the tips of the projections and the welding operation is performed.If the heights of the projections are not uniform, the metal member is inclined with respect to the base material. In many cases, welding is performed in a state in which the protrusions are formed. For this reason, it is necessary to control the protrusions with high accuracy, and a problem that the operation becomes complicated occurs.

In particular, it has been pointed out that when welding a nut member and a collar member to both sides of a base material, it is difficult to maintain the nut member and the collar member coaxially. Further, when the nut member and the collar member are welded to the base material while being inclined, the tightening force of the bolt is reduced, that is, so-called torque reduction is likely to occur. That is, FIG.
As shown in FIG. 1, a gap L is formed between the metal plate 1 and the nut member 2 in a welded joint 4 in which a nut member 2 and a collar member 3 are welded to both sides of a metal plate (base material) 1. In this case, after the mounting member 6 is fixed via the bolt 5, the metal plate 1 is distorted with the passage of time. For this reason, the tightening force of the bolt 5 is weakened, and the torque is reduced.

Accordingly, the base material is brought into contact with both surfaces of the base material, and the energization and the rest are repeated, so that the base material having a small thickness is welded to the base material first, and then the base material having the large thickness is welded. A three-layer projection welding method for welding a material and this basic base material has been proposed (see Japanese Patent Publication Nos. 3-24309 and 3-24310). However, in this type of conventional technology, each base material is provided with a welding protrusion, and if the heights of the welding protrusions are not uniform, the above-described problem cannot be solved.

The present invention has been made to solve this kind of problem, and there is no need to previously provide projections for projection welding on two metal members and a metal plate interposed therebetween, and the welding operation is easy and high. An object of the present invention is to provide a method for welding a welded joint that can be performed with high precision.

[0007]

In order to achieve the above-mentioned object, the present invention provides a method of interposing a metal plate between a first metal member and a second metal member; Pressing the metal members toward each other with a first pressing force, and pressing the first and second metal members with a second pressing force greater than the first pressing force; A step of engaging a corner provided on at least one of the metal plates with the metal plate, and supplying a first welding current using the corner as a projection welding projection in a state where the second pressing force is applied; A step of softening a joint between the first and second metal members and the metal plate, and a step of applying a second welding force larger than the first welding current in a state where the second welding force is applied after the first welding current is supplied. To supply the first and second metal members to the gold And having a step of integrally welded together via the plate member.

[0008]

In the method for welding a welded joint according to the present invention, the first and second metal members are provided on at least one of the first and second metal members by pressing them with the second pressing force. Since the corners are engaged with the metal plate and function as projection projections, the first and second metal members are integrally welded through the metal plate by supplying a welding current to the corners. Is done. At this time, in a state where the second pressing force is applied, the first welding current smaller than the second welding current necessary for the final welding is applied in advance, so that the first and second metal members and the metal plate material are connected to each other. Is softened so that the first and second metal members can be coaxially corrected, and then they are integrally welded.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for welding a welded joint according to the present invention will be described below with reference to the accompanying drawings.

Referring to FIGS. 1 and 2, reference numeral 10 is used.
Shows a welded joint for performing the welding method according to the present embodiment. The welded joint 10 includes a metal nut member (first metal member) 12, a metal collar member (second metal member) 14, the nut member 12 and the collar member 1.
4 and a metal plate 16 for coaxially and integrally welding them together.

A large-diameter flange portion 18 is provided at an end of the nut member 12, and a flat portion 20 of the flange portion 18 which is in contact with one surface of the metal plate material 16 has a disc-shaped inside thereof. To form an inner corner portion 22. An outer corner 26 is provided on the collar member 14 outside the flat portion 24 that is in contact with the other surface of the metal plate 16. The outer diameter φB of the outer corner 26 is set to be equal to or smaller than the inner diameter φA of the inner corner 22. Specifically, as shown in FIG. 1, the gap D between the inner corner portion 22 and the outer corner portion 26 has a relationship of 0 ≦ D ≦ 1.1t with respect to the plate thickness t of the metal plate 16. ing.

A through hole 28 is formed at the center of the collar member 14 and the through hole 28 is formed in the metal plate 16.
A hole 29 is formed corresponding to.

FIG. 2 shows a welding apparatus 30 for performing a welding process on the welded joint 10. This welding device 30
Is a lower electrode 32 on which the end of the collar member 14 is disposed.
And an upper electrode 34 for pressing the nut member 12 downward. An opening 36 formed in the lower electrode 32 includes
The positioning member 38 is provided so as to be able to advance and retreat.

Next, the welded joint 1 constructed as described above will be described.
The method of welding 0 will be described with reference to FIGS.

First, as shown in FIG. 2, the collar member 14 is disposed on the lower electrode 32 and the lower electrode 3
The positioning member 38 is inserted into the second opening 36 and the through hole 28 of the collar member 14. The metal plate 16 is disposed on the flat portion 24 of the collar member 14 with the holes 29 corresponding to the through holes 28, and the nut member 12 is placed on the metal plate 16.
Is arranged. This nut member 12 is used for positioning member 3.
8 and is positioned coaxially with the collar member 14.

Next, the upper electrode 34 is connected to the nut member 12.
The upper electrode 34 and the lower electrode 32 are pre-pressed with a predetermined first pressing force (pressing force) P1 in a direction approaching each other (FIGS. 3A and 4).
Middle, see (a)). Further, the upper electrode 34 and the lower electrode 3
2 is completely pressurized with a predetermined second pressing force (pressing force) P2, a gap D is formed between the inner corner portion 22 and the outer corner portion 26. Corner 26
Dig into the metal plate 16 from both sides of the metal plate 16 (see (b) in FIGS. 3B and 4).

In this state, the lower electrode 32 and the upper electrode 34
When a welding current A1 smaller than the welding current A2 required for welding is supplied for a time T1 (see (c) in FIGS. 3C and 4), the inner corner portion 22 and the outer corner portion are provided. 2
6 has a function as a projection for projection welding, the inner corner 22 and the outer corner 26 and the metal plate 1
6 is softened. Therefore, the second pressing force P2
The position of the nut member 12 and the collar member 14 is corrected coaxially via the positioning member 38 under the action of the above. Then, after the positioning member 38 is retracted, the energization is suspended for a time T2 and cooled, a welding current A2 is supplied for a time T3, and the inner corner 22 and the outer corner 26 and the metal plate 16 are melted. (See (d) in FIGS. 3d and 4).

As specific examples, the outer diameter φE of the flange portion 18 of the nut member 12 is 28 mm, the inner diameter φA of the inner corner portion 22 of the nut member 12 is 24 mm, and the outer diameter φB of the collar member 14 is 23 mm. The thickness t of the metal plate 16 is set to 1.6 mm. Further, a first pressing force P1 for preliminary pressurization = 200 kgf, and a second pressing force P1 for main pressurization.
2 = 800 kgf, welding current A1 = 1000 A is supplied only for time T1 = 0.04 seconds, and time T2 = 0.1
After a pause of seconds, the welding current A2 = 30000 A is supplied for a time T3 = 0.2 seconds.

In this case, in this embodiment, the nut member 12
When the second pressing force P2 is applied in a state where the metal plate 16 is sandwiched between the nut member 12 and the collar member 14, the inner corner portion 22 formed on the nut member 12 and the outer corner portion 26 formed on the collar member 14 are formed. Are cut into both sides of the metal plate member 16 and substantially function as projection welding projections. For this reason, as compared with the conventional method in which a ring-shaped projection or a plurality of projections for projection welding are provided in advance, the manufacturing operation of the nut member 12 and the collar member 14 as the welding members is simplified at a stroke, and the welded joint 10
The effect that the total manufacturing cost can be effectively reduced can be obtained.

Moreover, the nut member 12 and the collar member 14
In this state, the welding current A1 which is a small current is supplied in the state where the second pressing force P2 is applied, so that the inner corner portion 22 and the outer corner portion 26 are slightly melt-softened. Therefore, the welded portion between the inner corner portion 22 and the outer corner portion 26 and the metal plate 16 is easily deformed before the main welding, and the nut member 12 and the collar member 14 are positioned under the action of the second pressing force P2 via the positioning member 38. Can be coaxially corrected. As a result, in the present embodiment, this type of accuracy control is performed in comparison with the case where the accuracy of the protrusion itself has conventionally affected the product accuracy after welding, and thus it was necessary to control the protrusion with high accuracy. The effect is obtained that the entire welded joint 10 can be welded easily and accurately with no need.

If the distance D is larger than 1.1 t, the metal plate 16 is easily damaged by the inner corner 22 and the outer corner 26 when the second pressing force P2 is applied.

Further, in this embodiment, the inner corner portion 22 is provided on the horizontal flat portion 20 of the flange portion 18 of the nut member 12, while the outer corner portion 26 is provided on the horizontal flat portion 24 of the collar member 14. However, as shown in FIG. 5, the inner corner portion 22 can be provided on the inclined portion 50 of the flange portion 18, and the outer corner portion 26 can be provided on the inclined portion 52 of the collar member 14. The inclined portion 50 is inclined by an angle θ1 with respect to one side surface of the metal plate 16 while the inclined portion 52 is inclined.
Are inclined by an angle θ2 with respect to the other side surface of the metal plate 16. The angles θ1 and θ2 are preferably set in the range of 0 ° to 5 °, respectively.

Next, a welded joint 100 according to another embodiment is described.
Will be described. The same components as those of the above-described welded joint 10 are denoted by the same reference numerals, and a detailed description thereof will be omitted.

As shown in FIG. 6, this welded joint 100
A large-diameter flange portion 18 is provided at an end of the nut member 12 constituting the metal member 16.
In the flat portion 20 that is in contact with one surface of the metal plate 16, there is formed a tapered portion 102 that is notched in a truncated cone shape and that is inclined in a direction away from the metal plate 16. Color member 1
4 has a flat portion 24 in contact with the other surface of the metal plate 16.
Is provided with an outer corner portion 104 outside the outer corner portion 10.
The position 4 corresponds to the range H of the tapered portion 102.

The method for welding the welded joint 100 is as follows.
This method is substantially the same as the method of welding the welded joint 10 described above, and, when roughly described, after the nut member 12 and the collar member 14 are pressed by the first pressing force P1 (see FIG. 7A), the nut member 12 and the collar member 14 have the second pressing force P2.
Pressurized. At this time, the tapered portion 102 and the metal plate 1
6, a gap is formed between the metal plate 1
6 is deformed so that the tapered portion 102 is engaged with one surface of the metal plate 16, and the outer corner 26 is
6 dig into the other side (see FIG. 7b).

Therefore, when the welding currents A1 and A2 are supplied to the lower electrode 32 and the upper electrode 34 (see FIG. 7C), the outer corner portion 104 has a function as a projection welding projection. The tapered portion 102, the outer corner portion 104, and the metal plate 16 are melted and welded to each other (see FIG. 7D).

In this case, the welded joint 100 of this embodiment is
Has the same effect as the welded joint 10 described above,
By simply setting the position of the outer corner portion 104 within the range H of the tapered portion 102, the tapered portion 102 functions as a receiver for the outer corner portion 104, and the metal plate 16 can be effectively prevented from being damaged. .

Next, a welded joint 100 according to another embodiment is described.
8a to 100c are shown in FIGS. The same components as those of the above-described welded joint 100 include:
The same reference numerals are denoted by reference numerals a to c, and detailed description thereof will be omitted.

As shown in FIG. 8, in the welded joint 100a, the tapered portion 102a is directly formed without providing a flat portion at the end of the flange portion 18a of the nut member 12a.

In the welded joint 100b shown in FIG. 9, similarly to the welded joint 100a, a tapered portion 102b is provided directly from the end of the flange portion 18b of the nut member 12b, and an end of the collar member 14b in contact with the metal plate 16b. The inclined portion 106 is formed from the outer corner portion 104b without providing a flat portion in the portion.

Further, the welded joint 100c shown in FIG.
In the above, unlike the above-described welded joints 10, 100, 100a and 100b, the outer diameter of the nut member 12c is set smaller than the outer diameter of the collar member 14c. For this reason, an outer corner 108 in contact with the metal plate 16c is provided on the outer periphery of the nut member 12c, and the collar member 1
A tapered portion 110 that inclines inward is formed at an end of 4c that is in contact with the metal plate 16c.

The welded assembly 100a thus configured
The method of welding to 100c is the same as that of the welded joint 1 described above.
This is the same as the case of 00, and the respective effects are also the same.

[0033]

According to the method for welding a welded joint according to the present invention, the following effects can be obtained.

When a pressing force is applied after the metal plate is interposed between the first and second metal members, a corner provided on at least one of the first and second metal members becomes a metal plate. And function as projection welding projections. For this reason, it is not necessary to provide a projection for projection welding on the metal member in advance as in the related art,
The accuracy control becomes easy, and the manufacturing operation of the entire welded joint is simplified at a stroke, so that the manufacturing cost can be effectively reduced.

In addition, the first welding current smaller than the second welding current necessary for the final welding is applied in advance in a state where the second pressing force is applied to the first and second metal members. The first and second metal members can be coaxially corrected by softening a welded portion between the first and second metal members and the metal plate material, and then the first and second metal members can be subjected to main welding. Are coaxially and integrally welded.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a welded joint according to one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the welding assembly and the welding device.

FIG. 3 is a schematic explanatory view of a welding method of the welded joint.

FIG. 4 is an explanatory diagram of pressurization and energization timing of the welding method.

FIG. 5 is a partially longitudinal explanatory view of a modified example of the welded joint.

FIG. 6 is a partial longitudinal sectional view of a welded joint according to another embodiment of the present invention.

FIG. 7 is a schematic explanatory view of a welding method for a welded joint according to the other embodiment.

FIG. 8 is a partially longitudinal sectional view of a welded joint according to another embodiment.

FIG. 9 is a partial longitudinal sectional view of a welded joint according to still another embodiment.

FIG. 10 is a partial longitudinal sectional view of a welded joint according to yet another embodiment.

FIG. 11 is an explanatory view of a welded joint welded by a conventional welding method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Welded joint 12, 12a-12c ... Nut member 14, 14a-14c ... Collar member 16, 16a-16c ... Metal plate material 18, 18a-18c ... Flange part 22 ... Inner corner part 26 ... Outer corner part 30 ... Welding Apparatus 100, 100a to 100c: welded joint 102, 102a, 102b: tapered portion 104, 104a, 104b, 108: outer corner portion 110: tapered portion

Claims (3)

(57) [Claims] A step of interposing a metal plate between a first metal member and a second metal member; and a step of pressing the first and second metal members in a direction approaching each other with a first pressing force. The first and second metal members are pressed with a second pressing force greater than the first pressing force, and a corner provided on at least one of the first and second metal members is engaged with the metal plate. A step of supplying a first welding current using the corner portion as a projection welding projection in a state where the second pressing force is applied, and softening a joint portion between the first and second metal members and the metal plate material. And supplying a second welding current larger than the first welding current in a state in which the second pressing force is applied after the first welding current is supplied, to cause the first and second metal members to pass through the metal plate material. And a process of integrally welding and joining A welding method of a welded joint characterized by the above. 2. The welding method according to claim 1, wherein the first metal member has an inner corner inside a portion in contact with one surface of the metal plate, and the second metal member has an inner corner formed of the metal plate. An outer corner portion having an outer diameter set to be equal to or less than the inner diameter of the inner corner portion is provided outside a portion in contact with the other surface, and a second pressing force is applied, so that the inner corner portion is formed. A method for welding a welded joint, comprising a step of sandwiching both sides of the metal plate material with an outer corner. 3. The welding method according to claim 1, wherein the first metal member has a tapered portion inclined in a direction away from the metal plate inside a portion in contact with one surface of the metal plate. The second metal member has an outer corner set at a position corresponding to the outside of the portion in contact with the other surface of the metal plate member and within the range of the tapered portion, and a second pressing force is applied. A step of sandwiching the metal plate material between the tapered portion and the outer corner portion by welding.